In recent years, in IT systems (e.g., cloud infrastructure), operations are often made with allocation to users physical resources, such as “CPU” and “memory”, with units of logical resources, such as “virtual machine” and “volume”. There is a technique of operating IT systems using a system monitoring technique, such as baseline monitoring, in order to monitor performance information on IT systems having a complex relationship between user resources (e.g., logical resources to be recognized by users) and system resources (e.g., physical resources not to be recognized by the users). Such a type of technique can display a graph of performance information on a specific resource (e.g., a resource that causes an abnormality) in an IT infrastructure system. For example, the technique of PTL 1 can determine the bottleneck in a system where multiple virtual computers share physical resources, in consideration of the physical resource allocation policy and effects on software.